1. Field of the Invention
The invention relates to an apparatus for the detection of filterable gas contaminants and, more particularly, to such apparatus with a circular filter track which can be moved by action of a horizontal compact rotary plate over a suction pump with pump connection.
2. Description of the Prior Art
Such an apparatus is known from German Patent Publication Published for Opposition Purposes No. DE-AS No. 1 108 818, but this apparatus experiences problems involving forward movement, especially with relatively thin filter discs. This Federal Republic of Germany patent application published for opposition purposes and any patent issuing therefrom are incorporated herein by reference.
The detection of impurities, especially of pollutants in air, has been important for a long time, and has recently attracted increasing attention. Many contaminants can be filtered out of the air. Some, like aerosols or dusts, can be "screened" by an appropriate filter or collected by sorptive deposition on sorbents, such as activated carbon or zeolite. The detection of the concentrated pollutant on the filter or sorbent can be performed chemically or specifically by a physical-chemical analysis technique such as fluorescence analysis or a similar process.
In the area of monitoring of radioactivity, such a detection of air pollutants plays an altogether special role. Its sensitive detection of the radiation emitted is possible with the use of appropriate radiation-sensitive detectors.
Thus, there are presently devices for the detection of radioactive dusts and aerosols, in which a strip-like filter running over rollers is pulled in a stepwise manner over a gas-permeable support, which is connected with a suction system after the conclusion of the forward movement. Such an apparatus, with a constant forward movement, is described in German Patent Publication Published for Opposition Purposes No. DE-AS No. 1 147 326. The design of this known apparatus is relatively complicated, and its operation is not entirely satisfactory. This Federal Republic of Germany patent application published for opposition purposes and any patent issuing therefrom are incorporated herein by reference.